Department of Physical Medicine and Rehabilitation, Johns Hopkins University, Baltimore, Maryland, USA.
Laboratory of Vestibular NeuroAdaptation, Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University, Baltimore, Maryland, USA.
J Vestib Res. 2022;32(4):381-388. doi: 10.3233/VES-210106.
Patients with cerebellar ataxia report oscillopsia, "bouncy vision" during activity, yet little is known how this impacts daily function. The purpose of this study was to quantify the magnitude of oscillopsia and investigate its relation to vestibulo-ocular reflex (VOR) function and daily activity in cerebellar ataxia.
19 patients diagnosed with cerebellar ataxia and reports of oscillopsia with activity were examined using the video head impulse test (vHIT), Oscillopsia Functional Index (OFI), and clinical gait measures. Video head impulse data was compared against 40 healthy controls.
OFI scores in ataxia patients were severe and inversely correlated with gait velocity (r = -0.55, p < 0.05), but did not correlate with VOR gains. The mean VOR gain in the ataxic patients was significantly reduced and more varied compared with healthy controls. All patients had abnormal VOR gains and eye/head movement patterns in at least one semicircular canal during VHIT with passive head rotation.
Patients with cerebellar ataxia and oscillopsia have impaired VOR gains, yet severity of oscillopsia and VOR gains are not correlated. Patients with cerebellar ataxia have abnormal oculomotor behavior during passive head rotation that is correlated with gait velocity, but not magnitude of oscillopsia.
小脑性共济失调患者在活动时会出现视震颤，即“跳动的视觉”，但目前尚不清楚这对日常功能有何影响。本研究旨在定量评估视震颤的严重程度，并研究其与前庭眼反射（VOR）功能和小脑性共济失调患者日常活动的关系。
检查了 19 名被诊断为小脑性共济失调且伴有活动时视震颤的患者，使用视频头脉冲测试（vHIT）、视震颤功能指数（OFI）和临床步态测量进行评估。将视频头脉冲数据与 40 名健康对照进行比较。
共济失调患者的 OFI 评分严重，与步态速度呈负相关（r=-0.55，p<0.05），但与 VOR 增益无关。与健康对照组相比，共济失调患者的平均 VOR 增益明显降低且变化更大。在 VHIT 中，所有患者在至少一个半规管中进行被动头部旋转时，均出现异常的 VOR 增益和眼/头部运动模式。
患有小脑性共济失调和视震颤的患者存在 VOR 增益受损，但视震颤严重程度和 VOR 增益无相关性。小脑性共济失调患者在被动头部旋转时存在异常的眼动行为，与步态速度相关，但与视震颤的严重程度无关。
